There has been provided a synthetic resin bag having a freely closable zipper provided in an opening section of the bag body and an easy peel tape provided below the zipper.
It is a purpose of arrangement of the easy peel tape that an air-tight state is maintained within the bag body even though the zipper is opened and also that a liquid content contained within the bag body can be prevented from exuding out of the bag body.
However, closure means in the form of the easy peel tapes has an exudation prevention function of the fluid from the bag body to the exterior by a glue layer having a powerful adhesive strength, but it has a problem that the easy peel tape cannot be easily peeled off on the side of the opening section of the bag body.
Easily peeling off the tape from the opening section side can be accomplished by setting the adhesive intensity at 0.6 through 1.5 kg/15 mm, but this intensity is insufficient against a pressure from the bag interior section and therefore the kind, the weight, the filling rate etc. of the contents will be limited. In order to cancel such a default, the adhesive intensity of the easy peel tapes is required to be set at 2.0 through 4.0 kg/15 mm or more, but it will remain the problem that the peeling on the opening section side of the bag body is not easy.    Patent documents 1 JP,57-96952 A    Patent documents 2 JU57-105248A    Patent documents 3 JU62-38920Y    Patent documents 4 JP62-271847A    Patent documents 5 JP2-242748A    Patent documents 6 JU 6-14044A